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#pragma once

#include <QLayout>
#include <QRect>
#include <QStyle>

class flow_layout : public QLayout
{
public:
	struct position
	{
		int row{};
		int col{};

		operator bool() const { return row >= 0 && col >= 0; }
	};

	explicit flow_layout(QWidget* parent, int margin = -1, bool dynamic_spacing = false, int hSpacing = -1, int vSpacing = -1);
	explicit flow_layout(int margin = -1, bool dynamic_spacing = false, int hSpacing = -1, int vSpacing = -1);
	~flow_layout();

	void clear();
	const QList<QLayoutItem*>& item_list() const { return m_item_list; }
	const QList<position>& positions() const { return m_positions; }
	int rows() const { return m_rows; }
	int cols() const { return m_cols; }

	void addItem(QLayoutItem* item) override;
	Qt::Orientations expandingDirections() const override;
	bool hasHeightForWidth() const override;
	int heightForWidth(int) const override;
	int count() const override;
	QLayoutItem* itemAt(int index) const override;
	QSize minimumSize() const override;
	void setGeometry(const QRect& rect) override;
	QSize sizeHint() const override;
	QLayoutItem* takeAt(int index) override;

private:
	int horizontalSpacing() const;
	int verticalSpacing() const;
	int doLayout(const QRect& rect, bool testOnly) const;
	int smartSpacing(QStyle::PixelMetric pm) const;

	QList<QLayoutItem*> m_item_list;
	bool m_dynamic_spacing{};
	int m_h_space_initial{-1};
	int m_v_space_initial{-1};
	mutable int m_h_space{-1};
	mutable int m_v_space{-1};

	mutable QList<position> m_positions;
	mutable int m_rows{};
	mutable int m_cols{};
};
